793 research outputs found
Functional analysis of the transcription repressor PLU-1/JARID1B
No full textThe PLU-1/JARID1B nuclear protein, which is up-regulated in breast cancers, belongs to the ARID family of DNA binding proteins and has strong transcriptional repression activity. To identify the target genes regulated by PLU-1/JARID1B, we overexpressed or silenced the human PLU-1/JARID1B gene in human mammary epithelial cells using adenovirus and RNA interference systems, respectively, and then applied microarray analysis to identify candidate genes. A total of 100 genes showed an inversely correlated differential expression in the two systems. Most of the candidate genes were downregulated by PLU-1/JARID1B overexpression, including the metallothionein genes, the tumor suppressor gene BRCA1, and genes involved in the regulation of the M-phase of the mitotic cell cycle. Chromatin immunoprecipitation assays confirmed that the Metallothionein-1H, -1F and -1X genes are direct transcriptional targets of PLU-1/JARID1B in vivo. Furthermore the level of trimethyl H3K4 of the MT1H promoter was increased following silencing of PLU1/JARID1B. Both the PLU-1/JARID1B protein and the ARID domain selectively bound CG rich DNA. The GCACA/C motif, which is abundant in Metallothionein promoters, was identified as a consensus binding sequence of the PLU-1/JARID 1B ARID domain. As expected from the microarray data, cells over-expressing PLU-1/JARID1B have an impaired G2/M checkpoint. Our study provides insights into the molecular function of the breast cancer-associated transcriptional repressor PLU-1/JARID1B
A PLU-factorization of rectangular matrices by the Neville elimination
No full textAbstractIn this paper we prove that Neville elimination can be matricially described by elementary matrices. A PLU-factorization is obtained for any n×m matrix, where P is a permutation matrix, L is a lower triangular matrix (product of bidiagonal factors) and U is an upper triangular matrix.This result generalizes the Neville factorization usually applied to characterize the totally positive matrices. We prove that this elimination procedure is an alternative to Gaussian elimination and sometimes provides a lower computational cost
Biointerface analysis on a molecular level: new tools for biosensor research
No full textTiefenauer L, Ros R. Biointerface analysis on a molecular level: new tools for biosensor research. Colloids and surfaces, B: Biointerfaces. 2002;23(2-3):95-114.In the last decade various techniques have been developed to investigate biointerfaces on a molecular level. Here, their impact for biointerface analysis is reviewed with emphasis on biosensor research. In order to demonstrate the power and limitations of local probe methods the imaging and force spectroscopy on single molecules are presented in details
Characterisation and developmental expression of mouse Plu-1, a homologue of a human nuclear protein (PLU-1) which is specifically up-regulated in breast cancer
No full textPLU-1 is a novel breast cancer associated nuclear protein containing highly conserved domains including the PLU domain, putative DNA/chromatin binding motifs, and PHD/LAP domains. Here we report the cloning of the mouse homologue (Plu-1), and document its expression in adult tissues, mammary tumours and the embryo. The overall homology with human PLU-1 is 94% at the protein level, with almost 100% identity in the conserved domains, suggesting functional conservation. As with human PLU-1 the expression of Plu-1 in adult tissues is restricted, with high expression being seen only in testis, while expression in mammary tumours from c-neu transgenic mice is high. Plu-1 is also differentially expressed in the adult mammary gland. In the developing embryo Plu-1 is expressed in a temporally restricted fashion with tissue specific expression being limited to parts of the developing brain, whisker follicle, mammary bud, thymus, limbs, intervertebral disc, olfactory epithelium, teeth, eye, and stomach. The temporal and spatial expression patterns of the transcription factors Bf-1 and Pax9, recently found to bind to PLU-1 through the PLU domain overlap with Plu-1 expression during development. Thus Plu-1 appears to play an important role in mouse embryonic development which may involve interaction with Pax9 and Bf-1. (C) 2003 Elsevier Science Ireland Ltd. All rights reserve
PLU-1, a transcriptional repressor and putative testis-cancer antigen, has a specific expression and localisation pattern during meiosis.
No full textPLU-1, a large multi-domain nuclear protein with strong transcriptional repression activity, is a member of the ARID family of DNA binding proteins. In previous studies, high levels of expression of Plu-1 mRNA and PLU-1 protein were detected in breast cancers, while expression in normal adult tissues was detected only in the testis, ovary and transiently in the mammary gland of the pregnant female. Due to its high levels of expression in the testis and to its specific relationship to cancer, PLU-1 has been proposed to belong to the family of testis-cancer antigens. In this study we attempted to determine putative functions for PLU-1 during spermatogenesis. To address this, we analysed the pattern of expression and localisation of this protein in mouse testicular cells during postnatal development and adulthood. Using in situ hybridisation and immunostaining of testis sections we show that Plu-1 mRNA and PLU-1 protein are both highly expressed in the mitotic spermatogonia. Expression is reduced dramatically in the early prophase I stages (zygotene, leptotene), but reappears at pachytene and is still detectable in diplotene cells. We also found that PLU-1 localises diffusely over the nucleus, which indicates a potential chromatin binding ability of this protein. Consistent with this notion, we found that PLU-1 is present in the chromatin fraction in biochemical cell fractionation experiments using both somatic and meiotic cells. Our data point to a role for PLU-1 in meiotic transcription, which may be restricted to certain meiotic stages and may be mediated by the ability of this protein to associate with the chromatin
Chromatin and oxygen sensing in the context of JmjC histone demethylases
No full textResponding appropriately to changes in oxygen availability is essential for multicellular organism survival. Molecularly, cells have evolved intricate gene expression programmes to handle this stressful condition. Although it is appreciated that gene expression is co-ordinated by changes in transcription and translation in hypoxia, much less is known about how chromatin changes allow for transcription to take place. The missing link between co-ordinating chromatin structure and the hypoxiainduced transcriptional programme could be in the form of a class of dioxygenases called JmjC (Jumonji C) enzymes, the majority of which are histone demethylases. In the present review, we will focus on the function of JmjC histone demethylases, and howthese could act as oxygen sensors for chromatin in hypoxia. The current knowledge concerning the role of JmjC histone demethylases in the process of organism development and human disease will also be reviewed. © 2014 The Author(s) This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC-BY).</p
Las regiones fértiles de la tierra: nueva propuesta crítica a Plu., De facie 938D
No full textContribución al XII Congreso de la Sociedad Española de Plutarquistas (trienal).This paper trays to resolve the syntactical problem posed by the datives of the comparative phrase ὥσπερ ἄκροις τισὶν ἢ χερρονήσοις ἀνέχουσιν ἐκ βυθοῦ (Plu., De facie 938D), by changing into ἀνεχούσης the plural dativ ἀνέχουσιν we read in the codices E and B. On the other side, and as a consequence of the above solution, the author proposes to pay a greater attention to the alternative ἄκραις (instead of ἄκροις) which Turnebus and the Basilensis offer, may be as a lecture coming from a lost manuscript.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Bayesian marginal equivalence of elliptical regression models.
No full textThe use of proper prior densities in regression models with multivariate non-Normal elliptical error distributions is examined when the scale matrix is known up to a precision factor T, treated as a nuisance parameter. Marginally equivalent models preserve the convenient predictive and posterior results on the parameter of interest B obtained in the reference case of the Normal model and its conditionally natural conjugate gamma prior. Prior densities inducing this property are derived for two special cases of non-Normal elliptical densities representing very different patterns of tail behavior. In a linear framework, so-called semi-conjugate prior structures are defined as leading to marginal equivalence to a Normal data density with a fully natural conjugate prior.Multivariate elliptical data densities; Proper priors; Model robustness; Student t density;
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